The present invention relates to a new method for the manufacture of stationary and rotary comminuting members for pulp refining machines. Usually pulp stock is admitted and pumped through the comminuting members, thus refining and cutting, as desired, the fibrous wood stock.
As is already known, the refining discs have heretofore been made by casting and subsequent machining of a thick metal plate. As taught in U.S. Pat. No. 3,614,826, Mexican Pat. No. 103,742, Argentine Pat. No. 168,209, Brazilian Pat. No. 88,035 and Canadian Pat. No. 359,387, cold rolled upgraded steel bars are welded to a low-carbon steel body in accordance with the desired pattern and size of the blades or comminuting ribs.
In spite of the fact that said rib-welded construction is a substantial improvement both from the technical and economic viewpoints over prior art, it still has some disadvantages, for example in that it requires too much time to weld the steel blades individually to the supporting plate.
Moreover, the weld ridges resulting all along the base of the ribs have to be machined, to obtain smooth surfaces in order to reduce attrition in the flowing stock.